On Wed 2016-12-28T16:00:17 -0500, Brooks Harris hath writ: > I don't think so. This is POSIX so-called "1970-01-01 00:00:00 UTC" > not 1588/PTP. 1588/PTP epoch is 10s earlier.
At 1970-01-01 the difference TAI - UTC(BIH) was 8.000082 SI seconds. The first version of IEEE 1588 was not entirely consistent with its text and appendix information, so it was not clear whether that time scale was supposed to be TAI or TAI - 10. The second version of IEEE 1588 clarified that the intent is TAI. The choice of TAI - 10 would put the origin of the time scale at the intersection of the grey vertical line and the green horizontal line seen in the second plot on http://www.ucolick.org/~sla/leapsecs/amsci.html And for any system using that time scale that puts the origin at 1.999918 SI seconds after the (BIH average of the) radio broadcast time signals said it was 1970-01-01T00:00:00. But all of this is pedantic and moot for any currently operational system because it was not operational then. Only a few things like astrometry of solar system bodies and spindown of a handful of pulsars have data and models with enough precision to discern this. Everything and everyone else can reasonably assert that they do not have to care and that every day has always had 86400 seconds of duration equal to what they are currently ticking. -- Steve Allen <s...@ucolick.org> WGS-84 (GPS) UCO/Lick Observatory--ISB 260 Natural Sciences II, Room 165 Lat +36.99855 1156 High Street Voice: +1 831 459 3046 Lng -122.06015 Santa Cruz, CA 95064 http://www.ucolick.org/~sla/ Hgt +250 m _______________________________________________ LEAPSECS mailing list LEAPSECS@leapsecond.com https://pairlist6.pair.net/mailman/listinfo/leapsecs